Purpose – The purpose of this paper is to investigate whether stock price predictions and investment decisions improve by exposure to increasing price series. Design/methodology/approach – The authors conducted three laboratory experiments in which undergraduates were asked to role-play being investors buying and selling stock shares. Their task was to predict an unknown closing price from an opening price and to choose the number of stocks to purchase to the opening price (risk aversion) or the closing price (risk taking). In Experiment 1 stock prices differed in volatility for increasing, decreasing or no price trend. Prices were in different conditions provided numerically for 15 trading days, for the last 10 trading days, or for the last five trading days. In Experiment 2 the price series were also visually displayed as scatter plots. In Experiment 3 the stock prices were presented for the preceding 15 days, only for each third day (five days) of the preceding 15 days, or as five prices, each aggregated for three consecutive days of the preceding 15 days. Only numerical price information was provided. Findings – The results of Experiments 1 and 2 showed that predictions were not markedly worse for shorter than longer price series. Possibly because longer price series increase information processing load, visual information had some influence to reduce prediction errors for the longer price series. The results of Experiment 3 showed that accuracy of predictions increased for less price volatility due to aggregation, whereas again there was no difference between five and 15 trading days. Purchase decisions resulted in better outcomes for the aggregated prices. Research limitations/implications – Investors´ performance in stock markets may not improve by increasing the length of evaluation intervals unless the quality of the information is also increased. The results need to be verified in actual stock markets. Practical implications – The results have bearings on the design of bonus systems. Originality/value – The paper shows how stock price predictions and buying and selling decisions depend on amount and quality of information about historical prices.

Taken rational choice theory for granted, cooperation in social dilemmas may be seen as mysterious. In one-shot dilemmas where subjects unknown to one another interact and make their decisions anonymously, cooperation could even been regarded as lunacy. Several authors have challenged this view. Research has also identified various factors that imply why people cooperate or defect in social dilemmas and what motivations that might guide the decision in one way or the other. Here, a closer look will be taken at social norms as a reason for departure from rational choice, a factor that rarely has been recognized in the social dilemma literature. Social norms imply that people should manifest a prescribed behaviour or not manifest a proscribed behaviour. Furthermore, social norms are often guiding behaviour in specific contexts, and many times they need to be activated. Such an activation process is often unconscious and once a norm has been activated, people tend to keep following the norm that has been primed. We wish to add to the social dilemma literature by suggesting what kinds of norms that are likely to be activated under different conditions such as one-shot vs. repeated dilemmas, but also separate domains of social life.

Taking rational choice theory for granted, cooperation in social dilemmas may be seen as mysterious. In one-shot dilemmas where subjects unknown to one another interact and make their decisions anonymously, cooperation could even be regarded as lunacy. Several authors have challenged this view, though. Research has also identified various factors that imply why people cooperate or defect in social dilemmas and what motivations that might guide the decision in one way or the other. Here, a closer look will be taken at social norms as a reason for departure from rational choice, a factor that rarely has been recognised in the social dilemma literature. Social norms imply that people should manifest a prescribed behaviour or not manifest a proscribed behaviour. Furthermore, social norms are often guiding behaviour in specific contexts, and many times they need to be activated. Such an activation process is often unconscious and once a norm has been activated, people tend to keep following the norm that has been primed. We wish to add to the social dilemma literature by suggesting what kinds of norms that are likely to be activated under different conditions such as one-shot vs. iterated dilemmas, but also separate domains of social life.

Empirical evidence suggests that people´s maximum willingness to pay for having a good is often substantially lower than their minimum willingness to accept not having it, and that this discrepancy tends to be especially large when valuing public goods. This paper hypothesizes that differences in emotions (e.g. regret) and moral perceptions can account for much of this discrepancy for public goods. A simple, real-money dichotomous-choice experiment is set up to test these hypotheses, which are largely supported.

The aims of the present experiment were to investigate what information people in a public good dilemma base their ratings of fair cooperation rates on, and whether they tailor their ratings of fairness and their behavior to fit each other. Results indicate that the high correlations between fair and actual cooperation rates observed in previous research are misleading. When asked about fair de-grees of cooperation prior to making the own decision, people tailor their re-sponses. When the measures are separated in time, the correlations become more modest. Results also demonstrate that people use others behavior to determine what a fair degree of cooperation is

Consumer behaviour may be more or less guided by deliberate processes. In a deliberate phase, people are more attentive to, and, given the right circumstances, more influenced by values in their choice of products. When in a less deliberate phase consumers may fall back on habits and choose in a routine manner. This prediction was tested in a computer-based experiment, where participants purchased products in a simulated shop. They were randomly assigned to one of eight groups defined by whether they purchased under time pressure or not, whether an environmental value was primed or not, and whether ”organic food”-labels were salient or not. A discreetly placed “organic food”-poster at the entrance of the store was used to prime, or unobtrusively remind the consumer of an environmental value. Participants were unaware of this manipulation. As predicted, time pressure increased the likelihood of a habitual choice (as measured in a questionnaire) and inhibited directly value-guided choices. In addition, the poster, in combination with salient “organic food”-labels on the products, increased the likelihood of a choice directly guided by environmental values, but only under no time pressure.